<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>后代选择器</title>
    <style>
        div span {
            color: red;
        }
    </style>
</head>

<body>
    <!-- 
        后代选择器
        父元素的所有后代元素
     -->
    <div>
        <span>123</span>
        <p>
            <span>孙子</span>
        </p>
    </div>
</body>

</html>